Solar cells provide a means to produce electric power with minimal environmental impact because it is a renewable technology. In order to become a commercial success the solar cells need to be efficient, to have low cost, to be durable, and not add other environmental problems.
Today's dominant solar cell technology is based on crystalline silicon. It fulfils many of the requirements mentioned above but can not be produced at such low cost that electricity generation in large scale is cost effective. It also requires relatively large amount of energy in the production, which is an environmental disadvantage.
Solar cells based on thin film technologies have been developed. They offer a potential of substantial cost reductions but have, in general, lower conversion efficiencies and less good durability. A very promising thin film solar cell technology is based on the semiconductor Cu(In,Ga)Se2 (CIGS) which has demonstrated high efficiencies (16.6% in small prototype modules) and durability in operation.